Universal sound-transmitting means.



P. J. HACKETT.

UNIVERSAL SOUND TRANSMITTING MEANS.

APPLICATION FILED JULY 6. 1-914.

1,156,867. Patented 011. 12, 1915.

2 SHEETSSHEET l- L I 1 L? 29 1 J; M z,

P. J. HACKETT.

UNIVERSAL SOUND TRANSMITTING MEANS.

APPLICATION HLED JULY 6.1914. 1,156,867. Patented Out.12,19 15.

2 SHEETS-SHEET 2.

. I $4 1622 saw-ax, 6/474 4 22 272 07 nr -rrrcaga PAUL J. HAcKnr'ii orsEArrLn, wnsr me'rom ASSIGNOR TO UnivEnsAL HIGH rowan TELEPHONE COMPANY, or KING co N'rt, wasnmsron.

UNIVERS SOUND-TRANSMITTLLDTGZ To all whom it may concern 4 Be it known that 1, PAUL J. HA'oK 'r-a', a citizen of the United States, and a resident'of the city of Seattle, inthe county of King and State of Washington, have in" vented certain new and useful Improve ments in Unlversal Sound-Transmitting Means, of which the following is a full, true, and exact specification.

This invention relates to sound transmit ting means and has for its principal object to improve the construction shown and deg scribed in my prior application for United States patent serially numbered 793,460 and filed on the fourth (4th) day of October,

1913, in that my present invention provides means for utilizing the potential of? the human voice, for example, over a greater range of tones and over-tones than has heretofore been possible.

Other objects will appear'as the invention is more fully hereinafter described, illustrated in the accompanying drawings and pointed out in the" appended claims.

These objects are attained by the peculiar arrangement of associated stationary and moving electrodes in which one set of diaphragms, under the action of impinging sound waves upon their inner sidesfincreases the flow ofcurrent through their inclosed granule carbon variable resistance by compressing the said carbon, while the other set of diaphragms under the same influence has decreased the flow of current through the inclosed carbon granules by reducing the pressure upon the same. In this peculiar arrangement any given diaphragm operates against the physical resistance of only one inclosed carbon element, instead of two, as for instance that shown in my said prior application, and agalnst this resistance only when moving in one direction, lessens the friction and restraint to free vibration, thereby making the diaphragm much more sensitive to the impinging sound waves.

In the drawings, Figure 1 is a plan view with the outer casing removed. 4 Fig. 2 is.

' a side elevation of the same with the casing in place and looking in the direction of arrows 6; at. Fig. 3 is a section upon the line w x of Fig. 1. Fig. 4 is a section upon the line y-y of .Fig. 1. Fig. 5 is a wiring diagram of my device.

Referring now more particularly to the drawings, reference numeral 1 indicates a MEANS.

' Specification of Letters Patent. @gt, 12, 19 15,, mamas 'filed July 6, 1914. Serial No. 849,276.

from the said passage are similar passages 33, 4, 5., and 6. As sound waves are'set up within the mouthpiece 2 and the passage 1, through the human voice or otherwise, the said waves are deflect ed equally into the passages 3, 4;, 5 and 6 by reason of the pyramid 7 whose apex is coincident with the center of.the tube 1. The four planes of the pyramid face the four passages 3, i, 5, and 6 respectively, and the said pyramid is secured within a depression 8 in the joined tubes 3, 4L, and 6 by means of a screw 9. The outer ends of the tubes 3, 4t, 5, and 6 respectively are threaded as shown to rea but are preferably of about the proportion shown. The function of these holes is to clarify the sound transmitted by allowing the air to escape therethrough, rather than to return by way of-the tubes 3,4, 5'and 6, which return wouldcause interference with entering sound-waves; Bridges 13 and 13 crossthe centers of the disks 10 and 10, be-

ingsecured thereto byscrews 13*. Within the recesses 11 and 11 are diaphragms 14; and 15, respectii'ely, having insulated bands 16 around their peripheries. The said diaphragms are depressed centrally as at 14 and 15 and they are held in place by springs 17 which are secured to the disks 10 and 10 by means of screws 18, the inner ends of the springs 17 being insulated as at 19. Secured to the diaphragms 15 are mica disks 20 which are held by rings 20 and fastenings 20*. These disks cover the depressions 15. Through the centers of each of the disks 20 passes a spindle 21 which has a head 22 to'whicli is-secured a carbon electrode 23. The spindle 21 passes through a suitable bore in a collar 24. The said collar has a head 25 which bears against the mica disk 20 and is held thereto by a nut 21 on the end of the spindle 21 acting means of insulated screws 27 lhrough an (a data hole in the bottom oiithe depression bolt passes which has a head 29 and a nut 30 which serves to hold the bolt securely in place. Elecured to the head. of the bolt is an electrode 31. Between the fixed electrode 23 and the movable electrode 31 are carbon granules Secured to the bridges are terminal blocks 33 to which are secured terminal connections and 35. It will be readily understood that the electrode 23:3 is held stationary in the above mentioned case while the electrode 31 is movable, being held securely to the diaphragm.

Referring now more particularly to 1, 2 and 3, a case 36, having outstandi ,5 flanges 36 and open at its inner side, has a mica disk 37 secured over the said opening by means ot a ring 38 and tastenings 38. The said cast; disk and ring are supported from and secured to the diaphragm llby tubular supports 3!) which are positioned between the ring 38 and diaph'agin 14-. Passing through the flanges 36, disk 37, ring'38, tube 39 and diaphragm i l are bolts 40 having nuts all, said bolts and nuts holding the above mentioned parts securely toget-her. The cases 36 are provided with bolts :28, nuts 30 and electrodes 31, substantially the depressions 15 are provided. Disks 3'? are connected to spind 21 having heads 22 and nuts 2]., electrodes 23 and collars 52%, substantially the same as the disks 20. on hon. granules 32 separate the electrodes 23 and 31. Collars 24 are secured to the bridges lb by means of screws 27. The said collars are insulated from the hrid es by the insulations 13. By reference to 3 it will be readily understood that the electrode 23 is stationery and the electrode 31 is movable, being" connected to the diaphragm as described above. The four disks l and are secured to a circular casing member 42 by screws 4&2, which is in turn. secured to a stand 43. The outer casing i -l incloses all the mechanism of the device and is secured to casing member $22 by means of screws 4-5.

Referring now to wiring diagram in Fig. 5, diaphragnis 14 are connccte rl electri cally with the electrodes 31, which are con nected by wires 46 and 48 to wires -'-l-7 and 47% which in turn are connected to the di phragins 15. The said diaphragms are elec' trically connected to their electrodes 31. Wires i7 and 4:? load, one to each pole of a dynamo l8. Electrodes :23 are connected in pairs by wires elf) and 50 and 4-9" and 50 respectively. @ne each of the diayniragnis 14; and are connected by means of wires and 50" to the primary windings 51 of an induction coil 51, the latter (Jo-acting with a secondary coil -2. terminating in wires 53 which lead to the receiving end of a telephone system, not sh wn. 4

'lihe operation of the device is fob lows z-lfhen sound waves are set up Within the mouthpiece they travel downwardly and equally deflected by the pyramid I to'the tubes 3, a, 5, and 6, whence they travel to the respective diaphragms bl and 15 against which they impinge, causing the said diaphragms to swell outwardly which causes the granules 32, which are associated with the diaphragm 15, to be compressed between the electrodes of that diaphragm causing the granules to cohere to a greater degree than when the said diaphragins are at rest. The swelling action of the diaphragins lel,.on the other hand, causes its p'ranules 32 to be compressed to a less de- -ee than normal, with the result that the electrical current which was previously equally divided in its flow through the course outlined to diverge unequally, the greater portion thereof taking the course of least resistance through the granules which have just been pressed together by the said movement of the diaphragm 15, thence the greater part of the current. flows through the wire 49, wire 47, diaphragm 1.5, electrode 31, granule 32, electrode 23, bolt 2]. and wire 50 to the primary windings 5].,

returninn through the Wire 50% bolt 21, elec-' trod-c 23, granules QiEl I'OClb 31, diaphragin 15 and wire il -to the dynamo The device is the application of a Wheatstone bridge with resistance cup in eacl of the tour limbs, a source of current bridged between two opposite junctions ofthe re sistance elements, and a primary bridged between the other two junctions. Normally, no current flows as all the limbs are balanced but by the variation in resistance of the arious branches due to the action of the diaphragms, the balance is destroyed and current flows through the primary first in one direction and then in the other.

From the it will be seen that, due to the :fact that the carbon resistance cells, formed by the casings 36 and by the central depressions in the diaphragms 15, are so arranged that when sound waves swell the diaphragms outwardly, there is physical resistance offered by the granules to one diaphragm of each pair, but on the return nioveme or vibration of these diahhragins to which physical resistance has just been oil? cd "here is no physical resistance whatev r because there are no granules on that side of those dia iiiiragms, in contradistinction to such construction as that shown, for example, in my said previous application serially numbered 75.)?34-60, wherein there is physical resistance to the vibration of the diaphragms at all times. My present construction, therefore, is much more sensitive than the construction last mentioned. It will be understood that in my presen construction the diaphragins must be arranged in pairs, the diaphragm is, for example, being the complement of the diaphragm 15, and so on, and each diaphragm of each pair must, obviously, swell outwardly from the common source of sound, and, electrically considered, each diaphragm is oppositely disposed to its mate.

It will be noted that the holes 12: pass through thatportion of the disks l0 and 10 which is substantially parallel with the diaphragms H and 15. I am aware that it is common in the art to provide such holes as this, but not located in the same relative position with respect to the diaphragms as are the holes 12; that is to say, in an ordia nary telephone transmitter slots or holes occur through the sides of the mouthpiece which permit the air to escape before it can reach the diaphragms at all. The holes 12 are, therefore, purposely cut through the disks 10 and 1.0 and not through the side of the mouthpiece, so that the sound waves will surely strike the diaphragm first and then rebound out through the holes 12, which would not be the case ifth e said holes were in the mouthpiece proper.

I have shown and describeda particular form of embodiment of my invention but am aware that many changes therein will readily suggest themselves to others Without departing from the spirit and scope of the invention.

What I claim as new and desire to protect by Letters Patent is 1. The combination in an electrical soundtransmitting device having a plurality of sound tubescommunicating with a common source of sound, of a plurality of diaphf agms arranged in pairs, a granule resistance cell mounted upon each diaphragm, and a fixed and movable electrode within each of said cells whereby the granules associated with one diaphragm only of each pair are acted upon by the outwarl swelling of that diaphragm. O

2. The combination in an electrical soundtransmitting device having a. plurality. of

sound tubes communicating with a commbn source of sound, of a plurality of diaphragms arranged in pairs,a granule resistance cell mounted upon each diaphragm, and a fixed and a movable electrode within each of said cells whereby the granules associated with one diaphragm of each pair only are compressed by the outward swelling of that diaphragm and the corresponding granules of the other diaphragm of that pair are allowed to move away from each other.

3. The combination with a telephone transmitter of the type having a plurality of tubes communicating with a common sound passage and a diaphragm for each tube, of means for increasing the sensitiveness of the diaphragms, said means including an arrangement of the diaphragms in oppositely disposed pairs, a granular resistance cell affixed to each diaphragm and a fixed arid a movable electrode within each of said cells whereby when sound waves impinge against any of the said pans of diaphragms one dlaphragm of each pair compresses the granules within its resistance ,cell and the other diaphragm of that pair loosens the granules within its cell 4. The combination with a telephone transmitter having a common sound passage and diaphragms, of means for increasing the sensitiveness of the diaphragms, said means including an arrangement 01 the diaphragms in oppositely disposed pairs, a granular resistance cell aiiixed to each diaphragm and a fixed and a m'ilvable electrode within each of said cells whereby when sound waves impinge against any of the said pairs of diaphragms one diaphragm of each pair compresses the granules within its resistance cell and the other diaphragm of that pair loosens the granules within its resistance cell.

PAUL J. HACKETT.

\Vitnesses FRED P. GORIN, EMMA Kuosnn; 

